1. Field of the Invention
The invention relates to a sealing web (or roll) having at least one layer containing polymers of ethylene and propylene with or without a ter (third) component (EPDM/EPM). EPM is an elastomer obtained by the stereospecific copolymerization of ethylene and propylene. EPDM is an elastomer obtained by the stereospecific copolymerization of ethylene and propylene and a third monomer such as diene. The term terpolymer is sometimes used for polymerization products of three monomers. Ethylene-propylene copolymers (EPM), including ethylene-propylene terpolymers with dienes (EPDM) have been known for some time, U.S. Pat. No. 4,153,748, column 1, lines 62-64.
2. Description of the Prior Art
German DE-AS No. 2,628,741 (U.S. Pat. No. 4,153,748) discloses a covering which is resistant to the effect of water and climatic influences on the basis of EPDM. This covering consists of three layers with a vulcanizable inner layer of one or more foils containing a vulcanizing accelerator as well as of an upper layer and a lower outer layer of materials which does not contain vulcanization accelerator but are likewise vulcanizable. These layers are drawn individually and are vulcanized together on a vulcanizing machine and are thereby combined to form a three-layer structure. This covering, or at least its outer layers are weldable thermally and/or by solvents or swelling agents.
A disadvantage of this known covering is the very expensive fabrication of three different layers, to which may possibly be added a fourth layer, namely, a planar structure of textile material. In addition, difficulties regarding storability can exist if the accelerator content in the middle layer is high.